Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to techniques for vehicle-to-everything (V2X) communication systems in millimeter wave (mmWave or mmW).
Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources. These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example telecommunication standard is the 4th Generation (4G), which includes Long Term Evolution (LTE) and/or LTE-Advanced (LTE-A). In addition, the 5th Generation (5G) New Radio (NR) communications technology, used in a wide range of spectrum, is envisaged to expand and support diverse usage scenarios and applications with respect to current mobile network generations.
V2X communications can be used when a vehicle communicates with one or more entities or devices that may affect the vehicle, and vice versa. In an example, V2X communication may incorporate a specific type of communications, such as vehicle-to-vehicle (V2V) communications. In some examples, mmWave communications in a V2X communication system may have different features and requirements compared with conventional communication systems. For example, omni-directional links may not be available in mmWave band(s) (e.g., 10 GHz through 100 GHz) because of the path loss. In omni-directional transmissions, the path loss may scale as λ2, where λ is the carrier wavelength. In this case, when a wireless communication system moves from 2.4 GHz to 60 GHz, the path loss will be very high. In some cases, the path loss may reach 28 dB or larger. As such, mmWave links may be inherently directional, and the range or coverage of mmWave communications may depend on the beam width or directivity of a perspective beam being used. For instance, by using more antenna elements, the beams may be narrower, and may reach further in distance or cover more areas compared with using less antenna elements.
Accordingly, due to the requirements for increased data rates, higher throughput, and higher system reliability, new approaches or procedures may be desirable to improve connection setup and random access procedure (e.g., in a mmWave-based V2X communication system), and enhance medium access, in order to satisfy consumer demand and improve user experience in wireless communications.